Dillard's / problematic return

I purchased a queen comforter and small throw rug approx. 11 days ago; after careful consideration, I decided to return both items. After pulling out my receipt, I told the sales associate that I would like to return the items because I changed my mind. She scanned the POP tag and looked at my receipt- She then proceeded to tell me that I couldn't return the items because they had already been returned. "How is that possible? The items are right here. Please call your manager, " I asked her.
The manager came over and said that it could be done, but we would have to go to customer service. Again, the three employees kept stating that it had been returned yesterday at the Penn Square store (where I originally purchased the items).
At this point I started to feel as if I had done something wrong, and they still did not want to give me cash back ( I had paid by check that had already cleared my bank); they were going to give me a store credit.I told them no way- I want my money back.
Finally, they refunded my $123; the bedding manager did ask me "Are you sure you didn't try to return these things at Penn Square yesterday?" I was appalled! I hadn't even been to the Penn store since my purchase! What was he getting at? Why would I still have the items if I had returned them?
Finally, I collected my cash and told the customer service lady thank you, which I had to say THREE times before she acknowledged me. Also, they didn't give me back my old receipt or my refund receipt - which they have always done!
Needless to say, I felt like I had done something wrong- like I was a criminal. I was just waiting for the police to arrest me as I left the store.
I shop there a lot, but I honestly don't know if I want to go back.